A principal objective of this project is to develop laser inelastic light scattering techniques for performing measurements on biological cells and macromolecules. Theoretical analyses are performed in conjunction with various experimental studies: major emphasis is related towards problems of biological transport and cellular motility. Previously, experimental work was performed in laboratories located at the Massachusetts Institute of Technology and Columbia University. However, we are currently constructing an inelastic light scattering spectrometer for use at NIH, to be located in facilities being made available to us by the Laboratory of Biophysical Chemistry, NIAMDD. The next phases of instrument development will involve design and construction of apparatus for detecting electrophoretic mobilities and also, instrumentation for performing fluorescence intensity fluctuation spectroscopy. Laser inelastic light scattering techniques enable rapid and precise $ measurements of various physical parameters pertaining to biological molecules and cells. In principle, any process giving rise to refractive index fluctuations can be monitored; for example, concentration fluctuations can be used to determine diffusion coefficients of macromolecules, rate constants of bimolecular reactions, or swimming speed distributions of motile microorganisms.